Several benzodiazepines containing reactive functional groups were synthesized as specific, irreversible inhibitors of the benzodiazepine receptor in order to further study and characterize these receptors, through which the pharmacological properties of benzodiazepines are expressed. One of these inhibitors, Irazepine, binds irreversibly and specifically to the benzodiazepine receptor and represent the first example of this type of inhibitor. Irazepine is a relatively stable, crystalline substance and is easily prepared from known compounds in one step.